A recent NY Times article by Kim Severson proclaimed that "the entree is dead", noting that more people really just want a few bites of many things, as opposed to a giant main course, when they eat out. But to extrapolate from what New Yorkers do when they eat out at fine restaurants to the death of the entree is a bit extreme! As even the auther recognizes before quoting the top chefs in New York on the joys of small plates, appetizers, and tapas. Severson attributes the rise of appetizers and small plates to several trends: young people who personalize meals like an IPod play list; shortened attention spans; experimentation with a wide range of world flavors; and a trend away from the hegemony of the French fine dining model. A counter example is provided in the growing popularity of steak houses and a few New York chefs who buck the trend; Kerry Heffernan is quoted as saying, “There are times when you want to try everything on the planet, but more often than not you want to feel like you’ve been fed and nurtured and nourished. I think that comes from having your own plate.”
One thing Severson missed is that entrees have simply gotten too big in the last few decades, at fine restaurants as well as fast food chains. A full entree is usually too much to eat for most adults, and doggie bags are common (of course, some people simply skip the vegetables to shrink the meal). Entrees used to be part of a balanced meal - balanced, that is, between an appetizer, a main course, and the possibility of dessert; they still are in France (or were in 2002, anyway). But American entrees have gotten huge: 12 ounces of beef, a big pile of mashed potatoes, and veggies is a pretty normal plate, nearly twice as big as it should be. So maybe the shift to small plates is just that - maybe people are simply tired of wasting food or getting up from the table too full to enjoy. If entrees were down-sized, they might be more popular.
Even then, the trend is primarily in restaurants or for singles who don't have other people to cook for. Singles often find it simpler to eat a bit of that and a bit of that rather than cook a complete meal, but most American family meals are still protein, starch, and a veg, or a combination like a stir-fry or curry; it is traditional, but it is also an easy way to organize dinner night after night. This is part of what makes good home-cooked food so satisfying: there isn't much better food than a well-made, coherent meal with appropriate portion sizes and some variety in flavor. While the entree may be out of favor with trendy New Yorkers, I doubt it is going away any time soon in the rest of the country.